/*
  name - name of the cookie
  value - value of the cookie
  [expires] - expiration date of the cookie
    (defaults to end of current session)
  [path] - path for which the cookie is valid
    (defaults to path of calling document)
  [domain] - domain for which the cookie is valid
    (defaults to domain of calling document)
  [secure] - Boolean value indicating if the cookie transmission requires
    a secure transmission
  * an argument defaults when it is assigned null as a placeholder
  * a null placeholder is not required for trailing omitted arguments
*/

function setCookie(name, value, expires, path, domain, secure) {
  var curCookie = name + "=" + escape(value) +
  //       ((expires) ? "; expires=" + expires.toGMTString() : ""); +
	((path) ? "; path=" + path : "") +
	((domain) ? "; domain=" + domain : "") +
	((secure) ? "; secure" : "");
  document.cookie = curCookie;
}


/*
  name - name of the desired cookie
  return string containing value of specified cookie or null
  if cookie does not exist
*/

function getCookie(name) {
  var dc = document.cookie;
  var prefix = name + "=";
  var begin = dc.indexOf("; " + prefix);
  if (begin == -1) {
    begin = dc.indexOf(prefix);
    if (begin != 0) {
      return null;
    }
  } else {
    begin += 2;
  }

  var end = document.cookie.indexOf(";", begin);
  if (end == -1) {
    end = dc.length;
  }
  
  return unescape(dc.substring(begin + prefix.length, end));
}


/*
  name - name of the cookie
  [path] - path of the cookie (must be same as path used to create cookie)
  [domain] - domain of the cookie (must be same as domain used to
    create cookie)
  path and domain default if assigned null or omitted if no explicit
    argument proceeds
*/

function deleteCookie(name, path, domain) {
  if (getCookie(name)) {
    document.cookie = name + "=" +
    ((path) ? "; path=" + path : "") +
    ((domain) ? "; domain=" + domain : "") +
    "; expires=Thu, 01-Jan-70 00:00:01 GMT";
  }
}